CODEWITHSUNDEEP
tcptelnettelnetlib
Duanython
Duanython

Reputation: 1

Is there any telnet code ran in server after I initiate a telnet connection from client?

command in client There is what I input in client (192.168.0.106) tcp segment after I input the command There is what I capture immediately after I input the command

Is there any telnet code ran in server (freechess.org or 54.39.129.129)?

I know that there must be a process which listen port 5000 run in server after tcp established connection. But I am not sure whether telnet code run in server before or after the process which listen port 5000,

What I learn This is what I learned in youtube It seems that APPLICATIONS in last one picture corresponds to the process listening port 5000 in my example , am I right ?

Upvotes: 0

Views: 47

Answers (1)

Bob Goddard
Bob Goddard

Reputation: 977

You are misunderstanding the function of the command you are executing.

Telnet uses what was described as a network virtual terminal. Basically you connect to a port through which you issue commands and the server responds as required. These commands are ascii based

You are connecting to port 5000, all that means is that there is some daemon listening on that port to handle any connections.

Many unix commands use the same principle, that is it connects to a port and issues commands through it.

It just so happens that telnet allows you to attempt to connect to any tcp port, not just it's own port, 23.

Before nc came along, many of us would issue a similar command to test if there was a functioning port. Indeed, many of us would use it to connect to some smtp port to fire off a quick and dirty email to test functionality of the server if we had no client around. Test it yourself... run telnet <some email server> 25, you should get a banner. Then type in ehlo example.com. You get more info back.

Telnet is just a tool which is useful for far more than logging in to some remote system.

Upvotes: -1

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